Trimethylaminuria: an under-recognised and socially debilitating metabolic disorder

Primary flavin mono-oxygenase 3 deficiency, an inborn error of choline metabolism, leads to an accumulation of trimethylamine, which because of its associated pungent odour of rotting fish, is a socially crippling disorder. Although it often has its onset in early childhood, it may take years or even decades before the diagnosis is established. In this review the clinical biochemical and genetic features of the disorder are reported. The principles of therapy will also be covered, including dietary, pharmacological approaches, as well as techniques used to manipulate the gastrointestinal environment as a strategy to reduce the gastrointestinal load of trimethylamine.